Diacylglycerol kinase-α mediates hepatocyte growth factor-induced epithelial cell scatter by regulating Rac activation and membrane ruffling
Diacylglycerol kinase-α mediates hepatocyte growth factor-induced epithelial cell scatter by regulating Rac activation and membrane ruffling
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DOI：
10.1091/mbc.e07-02-0177
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发表时间：
2007-12-01
影响因子：
3.3
通讯作者：
Graziani, Andrea
中科院分区：
文献类型：
--
作者：
Chianale, Federica;Cutrupi, Santina;Graziani, Andrea
二酰基甘油激酶（Dgk）将二酰基甘油（DG）磷酸化为磷脂酸（PA），从而分别关闭和打开DG介导的和PA介导的信号传导途径。我们以前的研究表明，肝细胞生长因子（HGF），血管内皮生长因子，间变性淋巴瘤激酶激活Dgk α在内皮细胞和白血病细胞通过Src介导的机制和激活Dgka是所需的趋化，增殖和血管生成信号在体外。在这里，我们调查的下游事件和信号转导途径调节的Dgka，导致细胞分散和迁移后，肝细胞生长因子治疗和v-Src表达上皮细胞。我们报道了通过R59949处理或通过表达Dgka显性失活突变体或通过小干扰RNA介导的内源性Dgka的下调获得的Dgka的特异性抑制，损害1）HGF和v-Src诱导的细胞分散和迁移，而不影响细胞间粘附的丧失; 2）HGF诱导的细胞铺展、板状伪足形成、膜皱褶和局灶性粘连重塑;和3）HGF诱导的Rac活化和膜靶向。总之，我们提供的证据表明，Dgka，激活下游的酪氨酸激酶受体和Src，调节的关键步骤，指导Rac激活和Rac依赖的肌动蛋白细胞骨架和焦点接触迁移上皮细胞的重塑。
Diacylglycerol kinases (Dgk) phosphorylate diacylglycerol (DG) to phosphatidic acid (PA), thus turning off and on, respectively, DG-mediated and PA-mediated signaling pathways. We previously showed that hepatocyte growth factor (HGF), vascular endothelial growth factor, and anaplastic lymphoma kinase activate Dgk alpha in endothelial and leukemia cells through a Src-mediated mechanism and that activation of Dgka is required for chemotactic, proliferative, and angiogenic signaling in vitro. Here, we investigate the downstream events and signaling pathways regulated by Dgka, leading to cell scatter and migration upon HGF treatment and v-Src expression in epithelial cells. We report that specific inhibition of Dgka, obtained either pharmacologically by R59949 treatment, or by expression of Dgka dominant-negative mutant, or by small interfering RNA-mediated down-regulation of endogenous Dgka, impairs 1) HGF- and v-Src-induced cell scatter and migration, without affecting the loss of intercellular adhesions; 2) HGF-induced cell spreading, lamellipodia formation, membrane ruffling, and focal adhesions remodeling; and 3) HGF-induced Rac activation and membrane targeting. In summary, we provide evidence that Dgka, activated downstream of tyrosine kinase receptors and Src, regulates crucial steps directing Rac activation and Rac-dependent remodeling of actin cytoskeleton and focal contacts in migrating epithelial cells.